Impact of mismatch-repair deficiency on the colorectal cancer immune microenvironment.

ABSTRACT: Colorectal cancer patients respond inconsistently to immunotherapies, likely due to the immune microenvironments around their tumors. We analyzed the relationship between deficient mismatch repair (dMMR) and the colorectal cancer immune microenvironment to identify predictors of effective immunotherapy. Colorectal cancer patients (n=113) who had undergone surgical resection were divided into dMMR and proficient mismatch repair (pMMR) groups. The levels of immune checkpoint proteins, including programmed cell death 1 (PD-1), programmed cell death 1 ligand 1 (PD-L1), indoleamine 2,3 dioxygenase and CD8 were assessed immunohistochemically. The percentage of tumor-infiltrating lymphocytes strongly positive for PD-1 (score=3) was higher in the dMMR than pMMR group (79.3% vs. 41.7%; p=0.003). Th

SUBMITTER: Zhang Y 

PROVIDER: S-EPMC5689628 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature